1. Field of the Invention
Aspects of the present invention relate to an organic light-emitting display apparatus that operates as a touch screen.
2. Description of the Related Art
Recently, conventional display devices are being replaced by light-weight, thin, flat panel display devices. Among the flat panel display devices, self-emissive electroluminescent display devices, which can be classified as organic or inorganic, have wide viewing angles, high contrast ratios, and high response speeds, are considered to be the next-generation of display devices. Organic light-emitting display devices have a light-emitting layer formed of an organic material, improved brightness, driving voltages, and response speeds, and can produce a larger range of colors, in comparison to inorganic light-emitting display devices.
Organic light-emitting display apparatuses having a touch panel operation have been recently developed. In one approach, a display screen having a touch operation has been mounted in an organic light-emitting display apparatus, so that a command can be input by touching the display screen. The touch panel display screen used in this case includes a photo sensor.
However, in an organic light-emitting display apparatus having a conventional touch panel operation, light cannot be sensed efficiently in a dark environment. To solve this problem, a method of sensing light using internal light, emitted by an organic light-emitting diode, has been developed. However, when the light emitted by the organic light-emitting diode is deflected by the touch of a user, most of the light is absorbed before striking the photo sensor, and thus, the light reception efficiency of the photo sensor is low. Accordingly, even though the user touches the display screen, the touch cannot be sensed, or a malfunction may be generated, thereby increasing product defects, and decreasing user convenience.